1. Field of the Invention
The present invention relates to an analysis method, an analysis chip, and an analysis system.
2. Description of Related Art
Conventionally, glycation degrees of various proteins are analyzed for checking the condition of a living body. In particular, the glycation degree of hemoglobin (Hb) in blood cells is regarded as an important indicator in diagnosis, treatment, and the like of diabetes because it reflects the history of previous blood glucose levels in a living body. HbA1c, which is a typical example of hemoglobin used as such an indicator, is HbA(α2β2) with glycated valine at the N-terminal of the β-chain.
Examples of a method for analyzing Hb include electrophoresis methods. JP H11-337521A discloses an analysis method using an analysis chip that includes a capillary tube and an auxiliary flow path orthogonal to the capillary tube. A sample retained at an intersection of the capillary tube and the auxiliary flow path is analyzed in the electrophoresis method. This configuration is used in order to perform an accurate analysis with a very small amount of sample. WO 2008/136465 describes an analysis method that continuously supplies a sample also during separation of the sample by electrophoresis, in order to reduce the size of a chip for use in an analysis using an electrophoresis method.
However, according to the configuration of JP H11-337521A, before electrophoresis in the capillary tube, the linking space between the capillary tube and the auxiliary flow path has to be filled with a sample by the application of a voltage to two electrodes arranged at both ends of the auxiliary flow path. According to the configuration of WO 2008/136465, before the start of an analysis using the electrophoresis method, an electrophoretic liquid in the capillary tube may leak into a sample storage tank or the like. This leakage may significantly lower the precision of the analysis result. If the electrophoretic liquid that has leaked is concentrated by drying before the sample is introduced, a region excessively containing the components of the electrophoretic liquid may be formed at a portion of the sample that is to be analyzed first. Also, the electrophoretic liquid and the sample may be mutually diffused, forming a region having an unclear component ratio of the solution.